L'automatisation dans l'agriculture et dans l'industrie agro-alimentaire. Un exemple : le tri des fruits en fonction de leurs caractéristiques externes

Scientific conference (1997, May 15)

Séminaire de vulgarisation sur l'utilisation des techniques d'analyse d'image pour l'évaluation de la forme de fruit et pour la recherche de défauts.

Vision artificielle et quantification de la forme de pommes

in Cahiers Agricultures (1997), 6

Golden delicious apples were characterised automatically by machine vision, taking into account six view of the cheeks and one of the stem end. The Fourier transform of the fruit boundaries were computed ... [more ▼]

Golden delicious apples were characterised automatically by machine vision, taking into account six view of the cheeks and one of the stem end. The Fourier transform of the fruit boundaries were computed and normalised. All the relevant information about the shape was included in the first fifteen harmonics. Moreover, particular harmonics were found to characterise the shape of the Golden delicious variety. By using the amplitude of particular harmonics in a discriminant analysis, apple were sorted into categories defined by EU, with a precision around 96%. The proposed method may also be used to compare varieties objectively, in order to identify relation between physiology and shape. [less ▲]

The quality of 'Golden delicious' apples by colour computer vision

in Munack, A.; Tantau, H.-J. (Eds.) Mathematical and control application in agriculture and horticulture (1997)

A colour machine vision system was developed to form a basis for colour grading and defect inspection of 'Golden delicious' apples. The criteria were based on European Union standards and took into ... [more ▼]

A colour machine vision system was developed to form a basis for colour grading and defect inspection of 'Golden delicious' apples. The criteria were based on European Union standards and took into account commercial practices which add subclasses to the basic categories. The system was able to grade correctly more than 90% of the apple for colour (94% by using three colorimetric parameter R, G, B or H,S,I and 91% by using the single canonical variate) and ensured good defect detection (russet, scab, fungi attack, tec.). [less ▲]

Useful measurement techniques for comparing soil structure resulting from conventional cultivation and no-tillage

in Tebrügge, Franz (Ed.) Experience with the applicability of no-tillage crop production in the West-European countries (1994)

Different tillages including conventional and minimum tillages were conducted over several yers on a loamy soil, in Gembloux (Belgium). Numerous soil properties were measured to evaluate these tillage ... [more ▼]

Different tillages including conventional and minimum tillages were conducted over several yers on a loamy soil, in Gembloux (Belgium). Numerous soil properties were measured to evaluate these tillage practices on soil structure, workability, aeration, biological behaviour, ... with the final aim to establish the mechanisms to improve the yields and the economical returns of a given crop. The paper presents results concerning measurements of dry bulk density, soil structure and microrelief. [less ▲]

Effects of design and kinematic parameters of rotary cultivators on soil structure

in Soil & Tillage Research (1990), 17(3-4), 291-301

In comparison with drawn implements, rotary cultivators are of particular interest in final seedbed preparation. In this paper, a quantitative basis for the description of soil structure created by rotary ... [more ▼]

In comparison with drawn implements, rotary cultivators are of particular interest in final seedbed preparation. In this paper, a quantitative basis for the description of soil structure created by rotary tillers is given. Undisturbed Ap horizon samples were collected, impregnated with polyester resin, sectioned by sawing and analysed by means of image analysis. Total porosity, area and size of pores are related to the design and kinematic parameters of the rotary cultivator, arising from an analysis based upon the location of instant centres of velocity. It is shown that using a rotary cultivator with a higher ratio of peripheral to forward velocity leads to a smaller total mean porosity which is more homogeneous. [less ▲]

Ride simulation of seat suspensions for off-road vehicles.

in Agricultural Engineering. Proceedings of the 11th International Congress on Agricultural Engineering. (1989)

Ride vibration that occurs on agricultural tractors is injurious for the drivers because it affects their health and comfort. The aim of this study is to develop a model of an agricultural tractor and its ... [more ▼]

Ride vibration that occurs on agricultural tractors is injurious for the drivers because it affects their health and comfort. The aim of this study is to develop a model of an agricultural tractor and its trailer combination. The first model supposes that the trailer is rigidly bounded to the tractor. In the second one, the trailed is suspended by a spring. The effect of trailer attachment type on the dynamic behaviour is shown. [less ▲]

L'asservissement hydraulique des relevages de tracteurs agricoles

in Les commandes hydrauliques : conception et applications (1988)

Le relevage hydraulique des tracteurs assure, en plus de la montée et de la descente de l'outil attelé, des fonctions d'asservissement en position et en force de l'outil. En contrôle de position, la ... [more ▼]

Le relevage hydraulique des tracteurs assure, en plus de la montée et de la descente de l'outil attelé, des fonctions d'asservissement en position et en force de l'outil. En contrôle de position, la profondeur de travail de l'outil correspond à la consigne fixée par le conducteur. Avec l'asservissement en force, la profondeur de travail varie de façon à ce que la force de traction de l'outil corresponde à une consigne prédéterminée. Le but essentiel de cette commande est de créer un report de poids de l'outil sur le tracteur, pour optimiser les conditions d'adhérence de celui-ci. Précédemment, la liaison entre le capteur de déplacement ou de force et le distributeur hydraulique était purement mécanique. Les relevages électro-hydrauliques sont maintenant généralisés, avec des liaisons électriques entre les capteurs et l'électro-valve, contrôlée par micro-processeur. Outre la suppression de liaisons mécaniques compliquées, ces systèmes présentent de nombreux avantages tels que meilleure précision, temps de réponse plus court, possibilité d'un contrôle mixte position - force, ... [less ▲]

Measurement of soil surfaces profiles with an optical displacement transducer.

in Proceedings, 9th International Conference of the International Society for Terrain Vehicle Systems, held in Barcelona, Spain, 31 August-4September 1987. Volume 1. (1987), 1

Microrelief of seedbeds after two different soil tillages were measured with an optical displacement transducer. Measurements were made after sowing and on two successive dates. A complete statistical ... [more ▼]

Microrelief of seedbeds after two different soil tillages were measured with an optical displacement transducer. Measurements were made after sowing and on two successive dates. A complete statistical analysis was obtained by means of power spectra and autocorrelation functions. The authors suggest using the absolute value of the slope of the tangent at the origin of the autocorrelation function with the aim of analysing the behaviour of small particles in the scope of soil degradation [less ▲]